This invention is in the field of charge-coupled devices, hereinafter referred to as CCD, and particularly in a technique utilizing such devices as area imagers.
The response of detector cells in CCD area imagers typically varies in a random fashion by .+-.15%. This severely limits the imager sensitivity in point detection such as light from a star application.
Previous systems with discrete detectors have employed pre-programmed memories to store measured detector responsivity information which is used for normalization processing. This technique is unwieldy for the large numbers of detectors which can be fabricated in a monolithic form. Even if such off-chip memory would become manageable, transfer efficiency effects in the imager on the data stream would severely limit normalization accuracy.